554
FXUS63 KIWX 161742
AFDIWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
142 PM EDT THU APR 16 2026
KEY MESSAGES
- MORNING SHOWERS WILL GRADUALLY DISSIPATE TOWARD MID MORNING.
- ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED
TO DEVELOP AGAIN TODAY PARTICULARLY ACROSS NORTHEAST INDIANA,
SOUTH CENTRAL LOWER MICHIGAN, AND FAR NORTHWEST OHIO.
WIDESPREAD SEVERE WEATHER IS NOT EXPECTED, BUT A FEW SHOWERS
AND STORMS MAY PRODUCE WIND GUSTS TO 50 MPH AND SMALL HAIL
THIS AFTERNOON.
- MORE SHOWERS AND THUNDERSTORMS ARE EXPECTED LATE FRIDAY NIGHT
INTO SATURDAY. THERE IS SOME STRONG TO SEVERE WIND GUSTS WITH
THESE THUNDERSTORMS LATE FRIDAY NIGHT THROUGH MID AFTERNOON
SATURDAY.
- MUCH COOLER FOR SUNDAY BEHIND A COLD FRONT, BUT TEMPERATURES
MODERATE EARLY NEXT WEEK.
DISCUSSION
ISSUED AT 352 AM EDT THU APR 16 2026
A 55 TO 65 KNOT UPPER SPEED MAX PROGRESSING THROUGH SOUTHWEST UPPER
FLOW AND STRONG LOW LEVEL MOISTURE TRANSPORT IS AIDING IN
MULTIPLE CLUSTERS OF SHOWERS AND ISOLATED THUNDERSTORMS ACROSS
THE AREA. LOW LEVEL CIN HAS DEVELOPED LOCALLY WHICH SHOULD TEND
TO DECREASE THIS CONVECTION OVER NEXT FEW HOURS. SOME LINGERING
OUTFLOW HAS RESULTED IN SOME ISOLATED GUSTS OVER 40 MPH, AND
THIS MAY CONTINUE TO BE THE CASE THROUGH 10Z. WHILE ADDITIONAL
PRECIPITATION THIS MORNING MAY ONLY BE IN THE QUARTER TO HALF
INCH RANGE WITH THE HEAVIER POCKETS OF RAINFALL, THIS ADDED RAIN
IN AREAS WHICH HAVE EXPERIENCED HEAVY MULTI-DAY RAIN AMOUNTS
COULD LEAD TO SOME MINOR FLOODING. CURRENT EXPECTATION IS THAT
FLOOD WATCH WILL BE ALLOWED TO EXPIRE AT 12Z.
FOR TODAY, THE MORE AMPLIFIED UPPER LEVEL TROUGH WILL LIFT NORTHEAST
TO SOUTHEAST ONTARIO AS IT ENCOUNTERS AND DAMPENS THE STUBBORN MEAN
EASTERN CONUS UPPER RIDGE. THIS TRACK WILL MAKE FOR SLOW SOUTHEAST
PROGRESS TO LAGGING LOW LEVEL FRONT THIS AFTERNOON. DEEPER MOISTURE
AXIS SHOULD BE SHIFTING EAST OF THE LOCAL AREA THIS MORNING, BUT
COOLING ALOFT WITH THE UPPER LEVEL LOW TRACK SHOULD ALLOW FOR SOME
WEAK TO MODERATE SFC BASED INSTABILITY TO DEVELOP THIS
AFTERNOON (500-1200 J/KG). THE TRACK OF MID/UPPER LEVEL
REFLECTION WILL RESULT IN GRADUALLY WANING DEEP LAYER SHEAR
PROFILES TODAY, AND THUS NOT A GREAT CO-LOCATION OF
INSTABILITY/SHEAR PARAMETERS. AN ISOLATED STRONG TO SEVERE STORM
CANNOT BE COMPLETED RULED OUT ESPECIALLY IN A BRIEF WINDOW
DURING MID-LATE AFTERNOON CLOSER TO THE UPPER LEVEL SYSTEM WHERE
MID LEVEL LAPSE RATES ARE MAXIMIZED ACROSS NE IN/SC LOWER
MI/FAR NW OHIO, BUT OVERALL SEVERE THREAT TODAY IS SUBSTANTIALLY
LOWER THAN PREVIOUS FEW DAYS.
WITH ONLY A PARTIAL DAMPENING OF THE EASTERN CONUS RIDGING TODAY,
ASSOCIATED SFC BOUNDARY IS NOT EXPECTED TO MAKE SIGNIFICANT
SOUTHWARD PROGRESS TONIGHT AND WILL LIKELY STALL ACROSS NORTHERN
IN/NORTHWEST OH TONIGHT. WEAK FLOW IN VICINITY OF THIS TROUGH,
PARTIAL CLEARING AND LIKELY GOOD NEAR SFC MOISTURE LINGERING
BENEATH LOW LEVEL INVERSION SUGGEST POTENTIAL OF FOG FORMATION
TONIGHT.
MID LEVEL RIDGING QUICKLY AMPLIFIES THURSDAY NIGHT INTO FRIDAY
DOWNSTREAM OF A MORE SIGNIFICANT UPPER LEVEL TROUGH THAT WILL DIG
ACROSS THE ROCKIES ON FRIDAY. STRONG LOW LEVEL MOISTURE TRANSPORT
WILL BE CONFINED WEST OF THE LOCAL AREA FROM SOUTHERN PLAINS INTO
EASTERN IOWA ON FRIDAY WHICH IS WHERE CONVECTIVE INITIATION IS
EXPECTED. PROGRESSION OF THIS LONGWAVE FEATURE WILL INCREASE
CONVECTIVE CHANCES LOCALLY ESPECIALLY AFTER 06Z FRIDAY NIGHT.
UPSTREAM CONVECTIVE LINE SHOULD TEND TO OUTRUN BETTER INSTABILITY AS
IT REACHES WESTERN GREAT LAKES OVERNIGHT FRIDAY NIGHT, BUT POTENTIAL
EXISTS THAT SOME SEVERE WIND POTENTIAL COULD BE MAINTAINED INTO
WESTERN PORTIONS OF THE FORECAST AREA OVERNIGHT. STRONG BACKGROUND
WIND FIELDS SHOULD ALSO YIELD STRONG WESTERLY 0-3KM LINE NORMAL
SHEAR VECTORS WHICH COULD INDUCE SOME QLCS PROCESSES. FAR SOUTHEAST
PORTIONS OF THE FORECAST REMAIN IN SWODY3 MARGINAL RISK OUTLOOK,
WITH OVERALL TREND TO FAST FRONTAL PROGRESSION LIKELY LIMITING
SEVERE RISK LOCALLY FOR SATURDAY AFTERNOON.
SUNDAY AND MONDAY WILL FEATURE BELOW NORMAL TEMPS BEHIND THE
ASSOCIATED SATURDAY COLD FRONT BUT MID LEVEL HEIGHTS SHOULD RECOVER
LATE MONDAY IN ADVANCE OF A MORE BROAD SOUTH CENTRAL CANADIAN UPPER
TROUGH. A COOL FRONTAL BOUNDARY WITH THIS FEATURE WILL LIKELY GRAZE
SOUTHERN GREAT LAKES REGION FOR MIDDLE OF NEXT WEEK. IT DOES APPEAR
AS THOUGH WE COULD BE HEADED TO A MORE SEASONABLE TEMPERATURE
PATTERN NEXT WEEK WITH INDICATIONS IN MEDIUM RANGE GUIDANCE OF A
MORE STABLE LONGWAVE PATTERN DEVELOPING OF WESTERN CONUS TROUGH,
CENTRAL CONUS RIDGE, AND EASTERN CONUS TROUGH. THIS WOULD RESULT IN
MORE LIMITED DAY TO DAY THERMAL ADVECTIONS AND AT LEAST SOME BREAK
FROM THE ACTIVE RECENT SEVERE WEATHER PATTERN.
AVIATION /18Z TAFS THROUGH 18Z FRIDAY/
ISSUED AT 142 PM EDT THU APR 16 2026
THE UPPER TROF AND ASSOCIATED SFC LOW ARE TRANSLATING ACROSS
THE GTLKS REGION THIS AFTN AND EVENING. WHILE THE DEEPER
MOISTURE HAS SHIFTED EAST, SCTD SHOWERS HAVE DEVELOPED OVER NE
IL AND FAR NW IN AHEAD OF THE SFC TROF. HAVE INCLUDED THE
MENTION OF TSRA AT KSBN FOR THE FIRST FEW HOURS OF THE TERMINAL
FCST.
AS THE TROF SETTLES INTO THE REGION, WINDS DIMINISH, AND
RESIDUAL MOISTURE TRAPPED BENEATH A RATHER STRONG LLVL INVERSION
EXPECT CIGS TO LOWER AND VSBY DROP TO ONE MILE OR LOWER FOR
BOTH SITES. CONDITIONS SHOULD IMPROVE WITHIN A COUPLE OF HOURS
AFTER SUNRISE.
IWX WATCHES/WARNINGS/ADVISORIES
IN...NONE.
OH...NONE.
MI...NONE.
MARINE...NONE.
DISCUSSION...MARSILI
AVIATION...MF
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